我曾尝试使用official documentation上的教程使用Struts 2约定插件,但我无法运行它。
这是我配置它的方式:
pom.hml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>Struts2Convention</groupId>
<artifactId>Struts2Convention</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<build>
<sourceDirectory>src</sourceDirectory>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
<configuration>
<release>9</release>
</configuration>
</plugin>
<plugin>
<artifactId>maven-war-plugin</artifactId>
<version>3.2.1</version>
<configuration>
<warSourceDirectory>WebContent</warSourceDirectory>
</configuration>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>postgresql</groupId>
<artifactId>postgresql</artifactId>
<version>9.1-901-1.jdbc4</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.struts/struts2-core -->
<dependency>
<groupId>org.apache.struts</groupId>
<artifactId>struts2-core</artifactId>
<version>2.5.20</version>
</dependency>
<!-- https://mvnrepository.com/artifact/commons-logging/commons-logging -->
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
<version>1.2</version>
</dependency>
<!-- https://mvnrepository.com/artifact/commons-logging/commons-logging-api -->
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging-api</artifactId>
<version>1.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.struts/struts2-convention-plugin -->
<dependency>
<groupId>org.apache.struts</groupId>
<artifactId>struts2-convention-plugin</artifactId>
<version>2.5.20</version>
</dependency>
</dependencies>
</project>
网嗯
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" id="WebApp_ID" version="4.0">
<display-name>Struts2Convention</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>
我根据教程hello-world.jsp
和HelloWorld.java
创建了以下文件,这是动作类。
HelloWorld.Java
package com.example.actions;
import org.apache.struts2.convention.annotation.Action;
import com.opensymphony.xwork2.ActionSupport;
public class HelloWorld extends ActionSupport {
private String message;
public String getMessage() {
return message;
}
public String execute() {
message = "Hello World!";
return SUCCESS;
}
}
你好,world.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
hello world!
</body>
</html>
根据文档,
首先,Convention插件找到名为struts,struts2,action或actions的包。与这些名称匹配的任何包都被视为Convention插件的根包。接下来,插件查看这些包中的所有类以及子包,并确定这些类是否实现了com.opensymphony.xwork2.Action,或者它们的名称是否以Action结尾(即FooAction)。
我的设置看起来像这样
项目设置
运行tomcat时出现以下错误:
ERROR DefaultClassFinder Unable to read class [com.example.actions.HelloWorld]
java.lang.IllegalArgumentException
at org.objectweb.asm.ClassReader.<init>(Unknown Source)
at org.objectweb.asm.ClassReader.<init>(Unknown Source)
at org.objectweb.asm.ClassReader.<init>(Unknown Source)
at org.apache.struts2.convention.DefaultClassFinder.readClassDef(DefaultClassFinder.java:461)
at org.apache.struts2.convention.DefaultClassFinder.<init>(DefaultClassFinder.java:93)
at org.apache.struts2.convention.PackageBasedActionConfigBuilder.buildClassFinder(PackageBasedActionConfigBuilder.java:395)
at org.apache.struts2.convention.PackageBasedActionConfigBuilder.findActions(PackageBasedActionConfigBuilder.java:377)
at org.apache.struts2.convention.PackageBasedActionConfigBuilder.buildActionConfigs(PackageBasedActionConfigBuilder.java:333)
at org.apache.struts2.convention.ClasspathPackageProvider.loadPackages(ClasspathPackageProvider.java:52)
at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:206)
at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:66)
at org.apache.struts2.dispatcher.Dispatcher.getContainer(Dispatcher.java:957)
at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:463)
at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:496)
at org.apache.struts2.dispatcher.InitOperations.initDispatcher(InitOperations.java:73)
at org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:61)
at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:270)
at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:251)
at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:102)
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4516)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5162)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1377)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1367)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:902)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:831)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1377)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1367)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:902)
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:423)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:928)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.startup.Catalina.start(Catalina.java:638)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:350)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:492)
并且我的页面无法加载。我收到HTTP状态404错误。
我怎样才能解决这个问题?
我更改了pom.xml以排除asm 5.2并包含asm 7.1。在这个link中提到,在java 9,10,11中存在导致此问题的错误。
pom.hml
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>Struts2Convention</groupId>
<artifactId>Struts2Convention</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<build>
<sourceDirectory>src</sourceDirectory>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
<configuration>
<release>9</release>
</configuration>
</plugin>
<plugin>
<artifactId>maven-war-plugin</artifactId>
<version>3.2.1</version>
<configuration>
<warSourceDirectory>WebContent</warSourceDirectory>
</configuration>
</plugin>
</plugins>
<resources>
<resource>
<directory>src</directory>
</resource>
</resources>
</build>
<dependencies>
<dependency>
<groupId>postgresql</groupId>
<artifactId>postgresql</artifactId>
<version>9.1-901-1.jdbc4</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.struts/struts2-core -->
<dependency>
<groupId>org.apache.struts</groupId>
<artifactId>struts2-core</artifactId>
<version>2.5.20</version>
</dependency>
<!-- https://mvnrepository.com/artifact/commons-logging/commons-logging -->
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
<version>1.2</version>
</dependency>
<!-- https://mvnrepository.com/artifact/commons-logging/commons-logging-api -->
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging-api</artifactId>
<version>1.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.struts/struts2-convention-plugin -->
<dependency>
<groupId>org.apache.struts</groupId>
<artifactId>struts2-convention-plugin</artifactId>
<version>2.5.20</version>
<exclusions>
<exclusion>
<groupId>org.ow2.asm</groupId>
<artifactId>asm-tree</artifactId>
</exclusion>
<exclusion>
<groupId>org.ow2.asm</groupId>
<artifactId>asm-commons</artifactId>
</exclusion>
<exclusion>
<groupId>org.ow2.asm</groupId>
<artifactId>asm</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-core -->
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>2.11.2</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-core -->
<dependency>
<groupId>org.ow2.asm</groupId>
<artifactId>asm</artifactId>
<version>7.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.ow2.asm/asm-tree -->
<dependency>
<groupId>org.ow2.asm</groupId>
<artifactId>asm-tree</artifactId>
<version>7.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.ow2.asm/asm-commons -->
<dependency>
<groupId>org.ow2.asm</groupId>
<artifactId>asm-commons</artifactId>
<version>7.1</version>
</dependency>
</dependencies>
</project>